1
|
Tran RJ, Lalonde MS, Sly KL, Conboy JC. Mechanistic Investigation of HIV-1 Gag Association with Lipid Membranes. J Phys Chem B 2019; 123:4673-4687. [PMID: 31084006 DOI: 10.1021/acs.jpcb.9b02655] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An extensive investigation into the initial association of HIV-1 Gag with lipid membranes was conducted with second harmonic generation. The roles of the lipid phase, phospholipid 1,2-dioleoyl- sn-glycero-3-phospho-(1-myo-inositol-4,5-bisphosphate) [PI(4,5)P2], the presence of the myristoyl group on Gag, the C-terminus of Gag, and the presence of transfer ribonucleic acid (tRNA) in Gag-membrane association were examined using the physiologically most relevant full-length Gag protein studied thus far. The tighter packing of a bilayer composed of gel-phase lipids was found to have a lower relative amount of membrane-bound Gag in comparison to its fluid-phase counterpart. Rather than driving membrane association of Gag, the presence of PI(4,5)P2 and the myristoyl group were found to anchor Gag at the membrane by decreasing the rate of desorption. Specifically, the interaction with PI(4,5)P2 allows Gag to overcome electrostatic repulsion with negatively charged lipids at the membrane surface. This behavior was verified by measuring the binding properties of Gag mutants in the matrix domain of Gag, which prevented anchoring to the membrane either by blocking interaction with PI(4,5)P2 or by preventing exposure of the myristoyl group. The presence of tRNA was found to inhibit Gag association with the membrane by specifically blocking the PI(4,5)P2 binding region, thereby preventing exposure of the myristoyl group and precluding subsequent anchoring of Gag to the membrane. While Gag likely samples all membranes, only the anchoring provided by the myristoyl group and PI(4,5)P2 allows Gag to accumulate at the membrane. These quantitative results on the kinetics and thermodynamics of Gag association with lipid membranes provide important new information about the mechanism of Gag-membrane association.
Collapse
Affiliation(s)
- Renee J Tran
- Department of Chemistry , University of Utah , 315 South 1400 East, Room 2020 , Salt Lake City , Utah 84112 , United States
| | - Matthew S Lalonde
- Department of Biochemistry , University of Utah , 15 North Medical Drive East, Room 4100 , Salt Lake City , Utah 84112 , United States
| | - Krystal L Sly
- Department of Chemistry , University of Utah , 315 South 1400 East, Room 2020 , Salt Lake City , Utah 84112 , United States
| | - John C Conboy
- Department of Chemistry , University of Utah , 315 South 1400 East, Room 2020 , Salt Lake City , Utah 84112 , United States
| |
Collapse
|
2
|
Hunter CD, Guo T, Daskhan G, Richards MR, Cairo CW. Synthetic Strategies for Modified Glycosphingolipids and Their Design as Probes. Chem Rev 2018; 118:8188-8241. [DOI: 10.1021/acs.chemrev.8b00070] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Carmanah D. Hunter
- Alberta Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Tianlin Guo
- Alberta Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Gour Daskhan
- Alberta Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Michele R. Richards
- Alberta Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Christopher W. Cairo
- Alberta Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| |
Collapse
|
3
|
Jeong D, Ahn KS, Lee WY. Label-free impedimetric glycosensor based on β-galactose-functionalized gold electrode for the determination of cholera toxin. J Electroanal Chem (Lausanne) 2017. [DOI: 10.1016/j.jelechem.2017.10.064] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
4
|
Shen J, He F, Chen L, Ding L, Liu H, Wang Y, Xiong X. Liquid crystal-based detection of DNA hybridization using surface immobilized single-stranded DNA. Mikrochim Acta 2017. [DOI: 10.1007/s00604-017-2324-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
5
|
Benito-Peña E, Valdés MG, Glahn-Martínez B, Moreno-Bondi MC. Fluorescence based fiber optic and planar waveguide biosensors. A review. Anal Chim Acta 2016; 943:17-40. [PMID: 27769374 PMCID: PMC7094704 DOI: 10.1016/j.aca.2016.08.049] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 08/25/2016] [Accepted: 08/29/2016] [Indexed: 12/21/2022]
Abstract
The application of optical biosensors, specifically those that use optical fibers and planar waveguides, has escalated throughout the years in many fields, including environmental analysis, food safety and clinical diagnosis. Fluorescence is, without doubt, the most popular transducer signal used in these devices because of its higher selectivity and sensitivity, but most of all due to its wide versatility. This paper focuses on the working principles and configurations of fluorescence-based fiber optic and planar waveguide biosensors and will review biological recognition elements, sensing schemes, as well as some major and recent applications, published in the last ten years. The main goal is to provide the reader a general overview of a field that requires the joint collaboration of researchers of many different areas, including chemistry, physics, biology, engineering, and material science.
Collapse
Affiliation(s)
- Elena Benito-Peña
- Department of Analytical Chemistry, Faculty of Chemistry, Complutense University, 28040 Madrid, Spain
| | - Mayra Granda Valdés
- Department of Analytical Chemistry, Faculty of Chemistry, University of La Habana, 10400 La Habana, Cuba
| | - Bettina Glahn-Martínez
- Department of Analytical Chemistry, Faculty of Chemistry, Complutense University, 28040 Madrid, Spain
| | - Maria C Moreno-Bondi
- Department of Analytical Chemistry, Faculty of Chemistry, Complutense University, 28040 Madrid, Spain.
| |
Collapse
|
6
|
Ahn KS, Lim KR, Jeong D, Lee BY, Kim KS, Lee WY. Fluorescence energy transfer inhibition bioassay for cholera toxin based on galactose-stabilized gold nanoparticles and amine-terminated quantum dots. Microchem J 2016. [DOI: 10.1016/j.microc.2015.07.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
7
|
Liu C, Huang D, Yang T, Cremer PS. Simultaneous Detection of Multiple Proteins that Bind to the Identical Ligand in Supported Lipid Bilayers. Anal Chem 2015; 87:7163-70. [DOI: 10.1021/acs.analchem.5b00999] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Chunming Liu
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, United States
| | - Da Huang
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, United States
| | - Tinglu Yang
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, United States
- Department
of Chemistry, Penn State University, University Park, Pennsylvania 16802, United States
| | - Paul S. Cremer
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, United States
- Department
of Chemistry, Penn State University, University Park, Pennsylvania 16802, United States
- Department
of Biochemistry and Molecular Biology, Penn State University, University Park, Pennsylvania 16802, United States
| |
Collapse
|
8
|
Kim CS, Seo JH, Cha HJ. Functional interaction analysis of GM1-related carbohydrates and Vibrio cholerae toxins using carbohydrate microarray. Anal Chem 2012; 84:6884-90. [PMID: 22770420 DOI: 10.1021/ac301511t] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The development of analytical tools is important for understanding the infection mechanisms of pathogenic bacteria or viruses. In the present work, a functional carbohydrate microarray combined with a fluorescence immunoassay was developed to analyze the interactions of Vibrio cholerae toxin (ctx) proteins and GM1-related carbohydrates. Ctx proteins were loaded onto the surface-immobilized GM1 pentasaccharide and six related carbohydrates, and their binding affinities were detected immunologically. The analysis of the ctx-carbohydrate interactions revealed that the intrinsic selectivity of ctx was GM1 pentasaccharide ≫ GM2 tetrasaccharide > asialo GM1 tetrasaccharide ≥ GM3trisaccharide, indicating that a two-finger grip formation and the terminal monosaccharides play important roles in the ctx-GM1 interaction. In addition, whole cholera toxin (ctxAB(5)) had a stricter substrate specificity and a stronger binding affinity than only the cholera toxin B subunit (ctxB). On the basis of the quantitative analysis, the carbohydrate microarray showed the sensitivity of detection of the ctxAB(5)-GM1 interaction with a limit-of-detection (LOD) of 2 ng mL(-1) (23 pM), which is comparable to other reported high sensitivity assay tools. In addition, the carbohydrate microarray successfully detected the actual toxin directly secreted from V. cholerae, without showing cross-reactivity to other bacteria. Collectively, these results demonstrate that the functional carbohydrate microarray is suitable for analyzing toxin protein-carbohydrate interactions and can be applied as a biosensor for toxin detection.
Collapse
Affiliation(s)
- Chang Sup Kim
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 790-784, Korea
| | | | | |
Collapse
|
9
|
Lowe AM, Abbott NL. Liquid Crystalline Materials for Biological Applications. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2012; 24:746-758. [PMID: 22563142 PMCID: PMC3339119 DOI: 10.1021/cm202632m] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Liquid crystals have a long history of use as materials that respond to external stimuli (e.g., electrical and optical fields). More recently, a series of investigations have reported the design of liquid crystalline materials that undergo ordering transitions in response to a range of biological interactions, including interactions involving proteins, nucleic acids, viruses, bacteria and mammalian cells. A central challenge underlying the design of liquid crystalline materials for such applications is the tailoring of the interface of the materials so as to couple targeted biological interactions to ordering transitions. This review describes recent progress toward design of interfaces of liquid crystalline materials that are suitable for biological applications. Approaches addressed in this review include the use of lipid assemblies, polymeric membranes containing oligopeptides, cationic surfactant-DNA complexes, peptide-amphiphiles, interfacial protein assemblies and multi-layer polymeric films.
Collapse
Affiliation(s)
- Aaron M. Lowe
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, Wisconsin 53706
| | - Nicholas L. Abbott
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, Wisconsin 53706
| |
Collapse
|
10
|
Nguyen TT, Sly KL, Conboy JC. Comparison of the Energetics of Avidin, Streptavidin, NeutrAvidin, and Anti-Biotin Antibody Binding to Biotinylated Lipid Bilayer Examined by Second-Harmonic Generation. Anal Chem 2011; 84:201-8. [DOI: 10.1021/ac202375n] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Trang T. Nguyen
- Department of Chemistry, University of Utah, 315 South
1400 East, Rm. 2020, Salt Lake City, Utah 84112, United States
| | - Krystal L. Sly
- Department of Chemistry, University of Utah, 315 South
1400 East, Rm. 2020, Salt Lake City, Utah 84112, United States
| | - John C. Conboy
- Department of Chemistry, University of Utah, 315 South
1400 East, Rm. 2020, Salt Lake City, Utah 84112, United States
| |
Collapse
|
11
|
Chiriacò MS, Primiceri E, D'Amone E, Ionescu RE, Rinaldi R, Maruccio G. EIS microfluidic chips for flow immunoassay and ultrasensitive cholera toxin detection. LAB ON A CHIP 2011; 11:658-663. [PMID: 21127822 DOI: 10.1039/c0lc00409j] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A flow-injection impedimetric immunosensor for the sensitive, direct and label-free detection of cholera toxin is reported. A limit of detection smaller than 10 pM was achieved, a value thousands of times lower than the lethal dose. The developed chips fulfil the requirement of low cost and quick reply of the assay and are expected to enable field screening, prompt diagnosis and medical intervention without the need of specialized personnel and expensive equipment, a perspective of special relevance for use in developing countries. Since the chip layout includes two sensing areas each one with a 2 × 2 sensor array, our biochips can allow statistical or (alternatively) multiplex analysis of biorecognition events between antibodies immobilized on each working electrode and different antigens flowing into the chamber.
Collapse
|
12
|
Li Y, Wang Y, Yu H, Jiang J, Kong R, Shen G, Yu R. A Simple and Sensitive Piezoelectric Immunosensor for Cholera Toxin Based on GM1-Incorporated Liposome Agglutination. CHINESE J CHEM 2010. [DOI: 10.1002/cjoc.201090284] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
13
|
Hu Q, Jang CH. Liquid Crystal-based Imaging of Enzymatic Reactions at Aqueous-liquid Crystal Interfaces Decorated with Oligopeptide Amphiphiles. B KOREAN CHEM SOC 2010. [DOI: 10.5012/bkcs.2010.31.5.1262] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
14
|
Hartshorn CM, Jewett CM, Brozik JA. Molecular effects of a nanocrystalline quartz support upon planar lipid bilayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:2609-2617. [PMID: 20085365 DOI: 10.1021/la904308g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Supported lipid bilayer membranes play a vital role in a number of applications from biosensors to fundamental studies of membrane proteins. It is widely understood that the underlying solid support in such assemblies causes large perturbations to the lipid bilayer as compared with black lipid membranes, but the exact nature of these effects on the membrane by the solid support is less understood. Here, all-atom molecular dynamics simulations of DLPC, DMPC, POPC, and DEPC on a hydroxylated nanocrystalline alpha-quartz (011) slab have revealed a pronounced thinning effect. It is shown that this thinning effect proceeds by one of two mechanisms; the first is through a curling of the terminal methyl groups at the interface of opposing leaflets, and the second is through increased interdigitation of the alkyl chains. In all cases, it is shown that the thinning effect is accompanied by a commensurate spreading of the lipid membrane across the quartz substrate. Also, with the introduction of the solid support, a marked asymmetry in a number of structural properties is reported. These asymmetries include (a) the surface areas per lipid, (b) the electron probabilities of the polar headgroups, (c) the radial distributions of the choline groups, and (d) the average orientation of water surrounding the membranes. Finally, asymmetries associated with the different interaction energies within each system studied are reported. These unequal interaction energies lead to a net force holding the membrane to the surface of the support. It was found that direct membrane-substrate interactions play only a minor role in holding the membrane to the surface and it is the interstitial water that dominates these interactions. This is due to the fact that the water throughout the interstitial region displays an average orientational preference that is more favorable (attractive to the membrane and yields a higher number of hydrogen bonds) than water in the external region of the assembly.
Collapse
Affiliation(s)
- Christopher M Hartshorn
- Department of Chemistry, Washington State University, P.O. Box 644630, Pullman, Washington 99164-4630, USA
| | | | | |
Collapse
|
15
|
Polyakova SM, Belov VN, Yan SF, Eggeling C, Ringemann C, Schwarzmann G, de Meijere A, Hell SW. New GM1 Ganglioside Derivatives for Selective Single and Double Labelling of the Natural Glycosphingolipid Skeleton. European J Org Chem 2009. [DOI: 10.1002/ejoc.200900645] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
16
|
|
17
|
Protein Microarrays for the Detection of Biothreats. MICROARRAYS 2009. [PMCID: PMC7122912 DOI: 10.1007/978-0-387-72719-6_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Although protein microarrays have proven to be an important tool in proteomics research, the technology is emerging as useful for public health and defense applications. Recent progress in the measurement and characterization of biothreat agents is reviewed in this chapter. Details concerning validation of various protein microarray formats, from contact-printed sandwich assays to supported lipid bilayers, are presented. The reviewed technologies have important implications for in vitro characterization of toxin–ligand interactions, serotyping of bacteria, screening of potential biothreat inhibitors, and as core components of biosensors, among others, research and engineering applications.
Collapse
|
18
|
Dai X, Zhou F, Khan N, Huck WTS, Kaminski CF. Direct visualization of reversible switching of micropatterned polyelectrolyte brushes on gold surfaces using laser scanning confocal microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:13182-13185. [PMID: 18842063 DOI: 10.1021/la802066a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We apply confocal fluorescence microscopy for real time studies of reversible conformational changes of poly(methacryloyloxyethyl phosphate) (PMEP) brushes chemically grafted onto gold substrates. Oregon green 488 fluorophores chemically attached onto the PMEP polymers were used as reporters for probing the conformational changes. Use of a specially designed liquid flow microchamber allowed dynamic imaging of the brushes under varying environmental conditions. The fluorescence intensities exhibited fully reversible brightness changes on alternation of the solution in the chamber between water and KCl. This reversible quenching behavior is consistent with a conformational change between an extended and a collapsed brush configuration. The fluorescence quenching behavior of the brushes was found to be dependent on ion concentration as well as polymer grafting density and was caused by nonradiative energy transfer to the polymer scaffold and the gold substrate.
Collapse
Affiliation(s)
- Xiaowen Dai
- Department of Chemical Engineering, University of Cambridge, Cambridge, UK
| | | | | | | | | |
Collapse
|
19
|
Subramaniam V, D'Ambruoso GD, Hall HK, Wysocki RJ, Brown MF, Saavedra SS. Reconstitution of rhodopsin into polymerizable planar supported lipid bilayers: influence of dienoyl monomer structure on photoactivation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:11067-75. [PMID: 18759470 PMCID: PMC2726791 DOI: 10.1021/la801835g] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
G-protein-coupled receptors (GPCRs) play key roles in cellular signal transduction and many are pharmacologically important targets for drug discovery. GPCRs can be reconstituted in planar supported lipid bilayers (PSLBs) with retention of activity, which has led to development of GPCR-based biosensors and biochips. However, PSLBs composed of natural lipids lack the high stability desired for many technological applications. One strategy is to use synthetic lipid monomers that can be polymerized to form robust bilayers. A key question is how lipid polymerization affects GPCR structure and activity. Here we have investigated the photochemical activity of bovine rhodopsin (Rho), a model GPCR, reconstituted into PSLBs composed of lipids having one or two polymerizable dienoyl moieties located in different regions of the acyl chains. Plasmon waveguide resonance spectroscopy was used to compare the degree of Rho photoactivation in fluid and poly(lipid) PSLBs. The position of the dienoyl moiety was found to have a significant effect: polymerization near the glycerol backbone significantly attenuates Rho activity whereas polymerization near the acyl chain termini does not. Differences in cross-link density near the acyl chain termini also do not affect Rho activity. In unpolymerized PSLBs, an equimolar mixture of phosphatidylethanolamine and phosphatidylcholine (PC) lipids enhances activity relative to pure PC; however after polymerization, the enhancement is eliminated which is attributed to stabilization of the membrane lamellar phase. These results should provide guidance for the design of robust lipid bilayers functionalized with transmembrane proteins for use in membrane-based biochips and biosensors.
Collapse
Affiliation(s)
- Varuni Subramaniam
- Department of Chemistry, University of Arizona, Tucson, Arizona, 85721-0041
| | | | - H. K. Hall
- Department of Chemistry, University of Arizona, Tucson, Arizona, 85721-0041
| | - Ronald J. Wysocki
- Department of Chemistry, University of Arizona, Tucson, Arizona, 85721-0041
| | - Michael F. Brown
- Department of Chemistry, University of Arizona, Tucson, Arizona, 85721-0041
| | - S. Scott Saavedra
- Department of Chemistry, University of Arizona, Tucson, Arizona, 85721-0041
| |
Collapse
|
20
|
Chen H, Zheng Y, Jiang JH, Wu HL, Shen GL, Yu RQ. An ultrasensitive chemiluminescence biosensor for cholera toxin based on ganglioside-functionalized supported lipid membrane and liposome. Biosens Bioelectron 2008; 24:684-9. [PMID: 18672355 DOI: 10.1016/j.bios.2008.06.031] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2008] [Revised: 06/15/2008] [Accepted: 06/16/2008] [Indexed: 11/30/2022]
Abstract
A novel chemiluminescence biosensor based on a supported lipid layer incorporated with ganglioside GM1 was developed for the detection of cholera toxin. The planar supported lipid membrane was prepared as biosensing interface via spontaneous spread of ganglioside-incorporated phospholipid vesicles on the octadecanethiol-coated gold surface. The specific interaction of multivalent CT by ganglioside GM1 molecules enables the biosensor to be implemented via a sandwiched format using a liposome probe functionalized with GM1 and horseradish peroxidase (HRP). Then, the presence of the target CT could be determined via the HRP-catalyzed enhanced chemiluminescence reaction. The developed strategy offers several unique advantages over conventional biosensors in that it allows for an easy construction and renewal of the sensing interface, a small background signal due to low non-specific adsorption of serum constituents on the lipid membrane, and effective immobilization of multiple biocatalytic amplifiers and recognition components via common phospholipid reagents. The developed biosensor was shown to give chemiluminescence signal in linear correlation to CT concentration within the range from 1pgmL(-1) to 1ngmL(-1) with readily achievable detection limit of 0.8pgmL(-1).
Collapse
Affiliation(s)
- Huan Chen
- State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China
| | | | | | | | | | | |
Collapse
|
21
|
|
22
|
Brake JM, Abbott NL. Coupling of the orientations of thermotropic liquid crystals to protein binding events at lipid-decorated interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:8497-507. [PMID: 17595119 DOI: 10.1021/la0634286] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We report a study of the interactions of proteins with monolayers of phospholipids (D/L-alpha-dipalmitoyl phosphatidylcholine and L-alpha-dilauroyl phosphatidylcholine) spontaneously assembled at an interface between an aqueous phase and a 20-microm-thick film of a nematic liquid crystal (4'-pentyl-4-cyanobiphenyl). Because the orientation of the liquid crystal is coupled to the organization of the lipids, specific interactions between phospholipase A2 and the lipids (binding and/or hydrolysis) that lead to reorganization of the lipids are optically reported (using polarized light) as dynamic orientational transitions in the liquid crystal. In contrast, nonspecific interactions between proteins such as albumin, lysozyme, and cytochrome-c and the lipid-laden interface of the liquid crystal are not reported as orientational transitions in the liquid crystals. Concurrent epifluorescence and polarized light imaging of labeled lipids and proteins at the aqueous-liquid crystal interface demonstrate that spatially patterned orientations of the liquid crystals observed during specific binding of phospholipase A2 to the interface, as well as during the subsequent hydrolysis of lipids by phospholipase A2, reflect the lateral organization (micrometer-sized domains) of the proteins and lipids, respectively, at the aqueous-liquid crystal interface.
Collapse
Affiliation(s)
- Jeffrey M Brake
- Department of Chemical Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, USA
| | | |
Collapse
|
23
|
Chen YG, Zhao D, He ZK, Ai XP. Fluorescence quenching of water-soluble conjugated polymer by metal cations and its application in sensor. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2007; 66:448-52. [PMID: 16859983 DOI: 10.1016/j.saa.2006.03.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Revised: 03/21/2006] [Accepted: 03/23/2006] [Indexed: 05/11/2023]
Abstract
The effects of different metal cations on the fluorescence of water-soluble conjugated polymer (CP) and their quenching mechanism have been explored. Most transition metal cations, especially noble metal cations, such as Pd2+, Ru3+, and Pt2+ possessed higher quenching efficiency to CP fluorescence than that of the main group metal cations and other transition metal cations, which have filled or half-full outmost electron layer configurations. Base on this, rapid, sensitive detection of noble metal cations can be realized and a novel quencher-tether-ligand (QTL) probe was developed to detect avidin and streptavidin.
Collapse
Affiliation(s)
- Yan-Guo Chen
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China
| | | | | | | |
Collapse
|
24
|
Gamby J, Abid JP, Abid M, Ansermet JP, Girault HH. Nanowires Network for Biomolecular Detection Using Contactless Impedance Tomoscopy Technique. Anal Chem 2006; 78:5289-95. [PMID: 16878861 DOI: 10.1021/ac060479z] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Here we present the detection of ultralow concentrations of biomolecules in a device made from a polycarbonate membrane containing a network of gold nanowires and using a "contactless" impedance tomoscopy technique. The sensor comprises a thin dielectric layer with two parallel band electrodes on the one side and a microchannel containing gold nanowires onto which the adsorption of antibodies occurs. Upon applying a high-frequency ac voltage between the two electrodes, the adsorption process occurring at the surface of the gold nanowires can be followed through contactless impedance measurements. The configuration allows the real-time detection of biomolecules with a bulk concentration in the picomolar range.
Collapse
Affiliation(s)
- J Gamby
- Laboratoire d'Electrochimie Physique et Analytique, ISIC-Station 6, and Laboratoire de Physique des Matériaux Nanostructurés, IPN-Station 3, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | | | | | | | | |
Collapse
|
25
|
Gooding JJ. Biosensor technology for detecting biological warfare agents: Recent progress and future trends. Anal Chim Acta 2006. [DOI: 10.1016/j.aca.2005.12.020] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
26
|
Ngundi MM, Taitt CR, Ligler FS. Simultaneous determination of kinetic parameters for the binding of cholera toxin to immobilized sialic acid and monoclonal antibody using an array biosensor. Biosens Bioelectron 2006; 22:124-30. [PMID: 16431098 DOI: 10.1016/j.bios.2005.12.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2005] [Revised: 11/26/2005] [Accepted: 12/06/2005] [Indexed: 11/20/2022]
Abstract
Interactions between protein toxins and carbohydrate receptors are often semi-selective processes and the kinetic parameters that define the binding of a receptor to different toxins may vary with each interaction. In this study, we have determined the affinity constants for binding of cholera toxin (CT) to immobilized sialic acid and to anti-CT antibody (as a simultaneous reference) by measuring real-time binding processes using an array biosensor. N-Acetylneuraminic acid (Neu5Ac), a member of the sialic acid family, was covalently immobilized onto maleimide-activated planar waveguides via a thiol-terminated linker attached to the anomeric carbon of the sugar. Control antibodies were immobilized using two different approaches: covalent attachment onto maleimide-activated slides via the thiol on cysteine residues and non-covalent attachment using a biotin-NeutrAvidin linkage. Cy5-labeled CT was flowed over the immobilized receptors and the fluorescent intensity of the bound CT-receptor complex was recorded as a function of time. The association constants for CT binding to covalently attached Neu5Ac, to covalently attached anti-CT monoclonal antibody, and to antibody tethered by biotin-NeutrAvidin interactions were determined to be 1.3 x 10(8), 2.1 x 10(8) and 5.7 x 10(8)M(-1), respectively.
Collapse
Affiliation(s)
- Miriam M Ngundi
- Center for Bio/Molecular Science & Engineering, Naval Research Laboratory, Washington, DC 20375, USA
| | | | | |
Collapse
|
27
|
Affiliation(s)
- Raz Jelinek
- Department of Chemistry and Staedler Minerva Center for Mesoscopic Macromolecular Engineering, Ben Gurion University of the Negev, Beersheva 84105, Israel.
| | | |
Collapse
|
28
|
Ngundi MM, Taitt CR, McMurry SA, Kahne D, Ligler FS. Detection of bacterial toxins with monosaccharide arrays. Biosens Bioelectron 2005; 21:1195-201. [PMID: 15946840 PMCID: PMC1550354 DOI: 10.1016/j.bios.2005.05.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2005] [Revised: 04/15/2005] [Accepted: 05/03/2005] [Indexed: 10/25/2022]
Abstract
A large number of bacterial toxins, viruses and bacteria target carbohydrate derivatives on the cell surface to attach and gain entry into the cell. We report here the use of a monosaccharide-based array to detect protein toxins. The array-based technique provides the capability to perform simultaneous multianalyte analyses. Arrays of N-acetyl galactosamine (GalNAc) and N-acetylneuraminic acid (Neu5Ac) derivatives were immobilized on the surface of a planar waveguide and were used as receptors for protein toxins. These arrays were probed with fluorescently labeled bacterial cells and protein toxins. While Salmonella typhimurium, Listeria monocytogenes, Escherichia coli and staphylococcal enterotoxin B (SEB) did not bind to either of the monosaccharides, both cholera toxin and tetanus toxin bound to GalNAc and Neu5Ac. The results show that the binding of the toxins to the carbohydrates is density dependent and semi-selective. Both toxins were detectable at 100 ng/ml.
Collapse
Affiliation(s)
- Miriam M. Ngundi
- Center of Bio/Molecular Science & Engineering, Naval Research Laboratory, Washington, DC 20375, USA
| | - Chris R. Taitt
- Center of Bio/Molecular Science & Engineering, Naval Research Laboratory, Washington, DC 20375, USA
| | - Scott A. McMurry
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Daniel Kahne
- Department of Chemistry, Harvard University, Cambridge, MA, USA
| | - Frances S. Ligler
- Center of Bio/Molecular Science & Engineering, Naval Research Laboratory, Washington, DC 20375, USA
- * Corresponding author: Tel.: +1-202-404-6002; Fax: +1-202-404-8897; e-mail:
| |
Collapse
|
29
|
Martinez JS, Grace WK, Grace KM, Hartman N, Swanson BI. Pathogen detection using single mode planar optical waveguides. ACTA ACUST UNITED AC 2005. [DOI: 10.1039/b502329g] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
30
|
Worsfold O, Toma C, Nishiya T. Development of a novel optical bionanosensor. Biosens Bioelectron 2004; 19:1505-11. [PMID: 15093223 DOI: 10.1016/j.bios.2003.12.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2003] [Revised: 12/03/2003] [Accepted: 12/03/2003] [Indexed: 11/30/2022]
Abstract
We have developed a novel optical bionanosensor platform using a supported bilayer lipid membrane (SBLM), which has generic multi-analyte sensing capabilities. The SBLM is produced using a novel combination of ordered nanostructured thin film i.e. Langmuir-Blodgett (LB) and self-assembly deposition methodologies. A heptamer linear RGD (arginine-glycine-aspartate) containing peptide was covalently attached to a BODIPY (donor) lipid dye and utilised as an optical biosensor for integrin alpha(v)beta(3) loaded HUVEC's (sensitivity = 1000 cells ml(-1)). A second BODIPY (acceptor) lipid dye was integrated into the SBLM thus enabling signal amplification via a Forster resonance energy transfer (FRET) mechanism. The fluidity of the bilayer was confirmed via fluorescence recovery after photobleaching (FRAP) techniques and was performed without the need for fusogens.
Collapse
Affiliation(s)
- O Worsfold
- Frontier Research Division, Fujirebio Inc., 51 Komiya-cho, Hachioji-shi, Tokyo 192-0031, Japan.
| | | | | |
Collapse
|
31
|
|
32
|
Brake JM, Daschner MK, Luk YY, Abbott NL. Biomolecular interactions at phospholipid-decorated surfaces of liquid crystals. Science 2004; 302:2094-7. [PMID: 14684814 DOI: 10.1126/science.1091749] [Citation(s) in RCA: 378] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The spontaneous assembly of phospholipids at planar interfaces between thermotropic liquid crystals and aqueous phases gives rise to patterned orientations of the liquid crystals that reflect the spatial and temporal organization of the phospholipids. Strong and weak specific-binding events involving proteins at these interfaces drive the reorganization of the phospholipids and trigger orientational transitions in the liquid crystals. Because these interfaces are fluid, processes involving the lateral organization of proteins (such as the formation of protein- and phospholipid-rich domains) are also readily imaged by the orientational response of the liquid crystal, as are stereospecific enzymatic events. These results provide principles for label-free monitoring of aqueous streams for molecular and biomolecular species without the need for complex instrumentation.
Collapse
Affiliation(s)
- Jeffrey M Brake
- Department of Chemical and Biological Engineering, University of Wisconsin, Madison, 1415 Engineering Drive, Madison, WI 53706-1607, USA
| | | | | | | |
Collapse
|
33
|
Song X, Shi J, Swanson BI. Direct fluorescence-based detection methods for multivalent interactions. Methods Enzymol 2003; 362:523-42. [PMID: 12968386 DOI: 10.1016/s0076-6879(03)01035-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Affiliation(s)
- Xuedong Song
- Corporate Emerging Technologies, Kimberly-Clark Corporation, 1400 Holcomb Bridge Road, Roswell, Georgia 30076, USA
| | | | | |
Collapse
|
34
|
Hasegawa T, Yonemura T, Matsuura K, Kobayashi K. Artificial metalloglycoclusters: compact saccharide shell to induce high lectin affinity as well as strong luminescence. Bioconjug Chem 2003; 14:728-37. [PMID: 12862425 DOI: 10.1021/bc020026a] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tris-bipyridine ferrous and ruthenium complexes carrying various saccharide appendages have been investigated to develop sensory systems for monitoring saccharide-binding phenomena. Ferrous O-glycoclusters having spacer moieties inserted between saccharide appendages and the complex core showed enhanced affinities to lectins, but ferrous N-glycoclusters, in which the saccharide-appendages are directly linked to the complex core via amide linkage, had low lectin-affinities. Molecular dynamics calculation indicated that the O-glycoclusters have flexible and densely packed saccharide clusters, in contrast to the octahedrally fixed saccharide arrays of N-glycoclusters. Flexibility of saccharide clusters is essential for their enhanced affinity, probably to induce conformational change to fit the recognition sites of lectins. According to these insights, ruthenium O-glycoclusters have been designed as luminescence biosensors. The ruthenium complexes carrying alpha-manno clusters exhibited excellent affinities (IC(min) = 9.0 x 10(-)(8) M) to concanavalin A (ConA). It is suggested from conformational analysis that densely packed mannoclusters can be fit properly to the recognition site of ConA. The binding was enthalpicaly driven (deltaH degrees = -21.8 kcal/mol). This binding behavior is quite similar to that of 1-3/1-6 trimannoside to ConA. They have strongly amplified luminescence (Phi(em) = 0.15), and their luminescence intensities were changed (approximately 40%) upon binding to the specific lectins. The ruthenium glycoclusters can be a suitable sensory system for saccharide-binding phenomena.
Collapse
Affiliation(s)
- Teruaki Hasegawa
- Department of Molecular Design, Graduate School of Engineering, Nagoya University, Chikusa, Nagoya 464-8603, Japan
| | | | | | | |
Collapse
|
35
|
Lauer SA, Nolan JP. Development and characterization of Ni-NTA-bearing microspheres. CYTOMETRY 2002; 48:136-45. [PMID: 12116359 DOI: 10.1002/cyto.10124] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND For ease of purification, proteins are often expressed with a short affinity sequence of five or six adjacent histidine residues (His-tag). This His-tag binds to the metal of metal chelator complexes such as Ni(2+)-nitrilotriacetic acid (Ni-NTA) or -iminodiacetic acid (Ni-IDA). Chromatography resins bearing covalently attached metal chelator complexes are used widely for the easy affinity purification of His-tagged proteins or peptides. Because Ni-NTA microspheres were not commercially available at the beginning of our studies, we prepared and characterized such microspheres to immobilize His-tagged proteins and study their interactions. Our microspheres are of three types: (a) metal chelator complexes bound covalently to polystyrene microspheres, (b) metal chelator complexes bound covalently to silica microspheres, and (c) lipid-linked metal chelator complexes adsorbed to silica microspheres forming self-assembled bilayer membranes where the metal chelators have lateral mobility. METHODS The microspheres bearing covalently attached Ni-chelator were synthesized by reacting a primary amine-bearing Ni-NTA ligand with carboxy-functionalized microspheres and then loading with Ni(2+). Microspheres with laterally mobile metal chelator were made by incubating glass microspheres with liposomes containing phosphatidylcholine (PC) and the metal chelating lipid 1,2-dioleoyl-sn-glycero-3-[(N (5-amino-1-carboxypentyl)iminodiacetic acid)succinyl]. Binding of a His-tagged enhanced green fluorescent protein (EGFP) was used to characterize these microspheres by flow cytometry for their specificity, sensitivity, capacity and stability. RESULTS While all micospheres specifically bind His-tagged proteins, the conditions to achieve this are different for the polystyrene- and silica-based spheres. All three types of microspheres bind His-EGFP with saturation occurring at 30-50 nM and an apparent avidity (concentration of half-maximal binding) of approximately 1 to 2 x 10(-8) M at pH 7.4. Binding of His-EGFP is inhibited by imidazole or ethylene-diaminetetraacetic acid (EDTA). Polystyrene Ni-NTA microspheres showed significant nonspecific binding as measured by binding in the presence of imidazole or EDTA or by binding of fluorescent proteins lacking a His-tag. This nonspecific binding of proteins to and aggregation of polystyrene spheres could only be prevented by the inclusion of low concentrations of Tween 20, but not by including bovine serum albumin (BSA), polyethylene glycols, or polyvinylpyrrolidones as blocking agents. In contrast, silica-based microspheres with covalently attached Ni-NTA or silica microspheres bearing adsorbed bilayers that contain Ni-NTA-lipid showed little nonspecific binding in the presence of BSA. Our results on the stability of immobilization indicate that washing destabilizes the binding of His-tagged proteins to Ni-NTA microspheres. This binding consists of two interactions of different affinities. We also demonstrate that limited multiplexed analysis with differently sized silica microspheres bearing the Ni-NTA-lipid is feasible. CONCLUSIONS The microspheres described are well suited to selectively immobilize His-tagged proteins to analyze their interactions by flow cytometry. The affinity and kinetic stability of the interaction of His-tagged proteins with Ni-NTA are insufficient to use Ni-NTA microspheres in multiplexed analysis formats where different His-tagged proteins are bound to distinct microspheres. Improvements towards this end (improved chelators and/or improved affinity tags) are critical for extending the use of this method. We are currently working on novel chelators to strengthen the stability of immobilization of His-tagged proteins to surfaces. Such improvements would greatly enhance the analysis of interactions of immobilized His-tagged proteins and could make the development of microsphere-based arrays with His-tagged protein/antibody possible.
Collapse
Affiliation(s)
- Sabine A Lauer
- Bioscience Division and National Flow Cytometry Resource, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
| | | |
Collapse
|
36
|
|
37
|
|
38
|
Song X, Shi J, Nolan J, Swanson B. Detection of multivalent interactions through two-tiered energy transfer. Anal Biochem 2001; 291:133-41. [PMID: 11262166 DOI: 10.1006/abio.2001.5024] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A method based on two-tiered fluorescence resonant energy transfer (FRET) has been developed for selective and sensitive detection of species involved in a multivalent interaction. Pentavalent binding between cholera toxin and ganglioside GM1 is used as a model system to demonstrate the advantage of the two-tiered FRET over one-stage FRET in both conventional fluorimeter and flow cytometer. In the system, three fluorescent probes (namely, fluorescence donor, acceptor, and intermediate) are covalently tagged to receptors, and the intermediate is used to bridge the energy transfer between the donor and acceptor even though the donor's fluorescence spectrum does not overlap with absorption spectrum of the acceptor. One of the most significant improvements of the scheme over one-stage FRET is a dramatic decrease in the background fluorescence of the acceptor fluorescence, which, theoretically and practically, increases the detection sensitivity.
Collapse
Affiliation(s)
- X Song
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
| | | | | | | |
Collapse
|
39
|
Song X, Shi J, Swanson B. Flow cytometry-based biosensor for detection of multivalent proteins. Anal Biochem 2000; 284:35-41. [PMID: 10933853 DOI: 10.1006/abio.2000.4664] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Microsphere-based flow cytometric detection of cholera toxin (CT) through distance-dependent fluorescence resonant energy transfer (FRET) has been developed. Simultaneous double-fluorescence changes induced by multivalent interactions between CT and fluorophore (both fluorescence donor and acceptor)-labeled ganglioside GM1 on a biomimetic membrane surface (supported bilayers of phospholipids) can be measured by a commercial flow cytometer, providing a convenient and sensitive detection method for CT. The flow cytometry-based biosensor is capable of detecting less than 10 pM CT within 30 min. The signal generation strategy coupled with flow cytometry also provides a convenient method for kinetic studies of multivalent interactions. The surface density and the ratio of donor/acceptor-labeled GM1 on the surfaces of phospholipid bilayers are optimized to achieve high sensitivity.
Collapse
Affiliation(s)
- X Song
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA.
| | | | | |
Collapse
|
40
|
Rowe-Taitt CA, Cras JJ, Patterson CH, Golden JP, Ligler FS. A ganglioside-based assay for cholera toxin using an array biosensor. Anal Biochem 2000; 281:123-33. [PMID: 10847619 DOI: 10.1006/abio.2000.4571] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A rapid assay for cholera toxin (CT) has been developed using a fluorescence-based biosensor. This sensor was capable of analyzing six samples simultaneously for CT in 20 min with few manipulations required by the operator. The biochemical assays utilized a ganglioside-"capture" format: ganglioside GM1, utilized for capture of analyte, was immobilized in discrete locations on the surface of the optical waveguide. Binding of CT to immobilized GM1 was demonstrated with direct assays (using fluorescently labeled CT) and "sandwich" immunoassays (using fluorescently labeled tracer antibodies). Limits of detection for CT were 200 ng/ml in direct assays and 40 ng/ml and 1 microg/ml in sandwich-type assays performed using rabbit and goat tracer antibodies. Binding of CT to other glycolipid capture reagents was also observed. While significant CT binding was observed to loci patterned with GD1b, Gb3, and Gb4, CT did not bind significantly to immobilized GT1b at the concentrations tested. This is the first description of such a non-antibody-based recognition system in a multi-specific planar array sensor.
Collapse
Affiliation(s)
- C A Rowe-Taitt
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375, USA
| | | | | | | | | |
Collapse
|
41
|
Kelly D, Grace KM, Song X, Swanson BI, Frayer D, Mendes SB, Peyghambarian N. Integrated optical biosensor for detection of multivalent proteins. OPTICS LETTERS 1999; 24:1723-1725. [PMID: 18079915 DOI: 10.1364/ol.24.001723] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We have developed a simple, highly sensitive and specific optical waveguide sensor for the detection of multivalent proteins. The optical biosensor is based on optically tagged glycolipid receptors embedded within a fluid phospholipid bilayer membrane formed upon the surface of a planar optical waveguide. Binding of multivalent cholera toxin triggers a fluorescence resonance energy transfer that results in a two-color optical change that is monitored by measurement of emitted luminescence above the waveguide surface. The sensor approach is highly sensitive and specific and requires no additional reagents and washing steps. Demonstration of protein-receptor recognition by use of planar optical waveguides provides a path forward for the development of fieldable miniaturized biosensor arrays.
Collapse
|